The netrins are a small family of axonal guidance proteins that can attract or
repulse growing axons during neural development. During development of the
retina, retinal ganglion cells (RGCs) axons are attracted by a netrin source at the
optic disc that permits them to exit the retina and form the optic nerve. To
characterise the role of netrins in the adult visual system, we investigated the
expression of netrins and their receptors in the adult mouse retina.
While expression of netrin-1 has not been detected in the adult retina, netrin-
3 has been abundantly found in RGCs amacrine cells. We also demonstrate that
netrin receptors are expressed in the adult retina. DCC was found to be restricted in
RGCs axons and neogenin in dendrites of RGCs and horizontal cells. UNC5B
proteins were detected at RGC soma and UNC5C proteins in the Müller cells.
The finding that netrin-3 and its receptors are abundantly expressed in many
cell types of the adult retina suggests a funtional role for them in the mature visual
system.